ext4: make ext4_show_options() be table-driven

Consistently show mount options which are the non-default, so that
/proc/mounts accurately shows the mount options that would be
necessary to mount the file system in its current mode of operation.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 61 insertions, 111 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7e3a319ec402..70828699fa89 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1198,8 +1198,8 @@ static const match_table_t tokens = {
         {Opt_nouser_xattr, "nouser_xattr"},
         {Opt_acl, "acl"},
         {Opt_noacl, "noacl"},
-        {Opt_noload, "noload"},
         {Opt_noload, "norecovery"},
+        {Opt_noload, "noload"},
         {Opt_removed, "nobh"},
         {Opt_removed, "bh"},
         {Opt_commit, "commit=%u"},
@@ -1668,6 +1668,16 @@ static inline void ext4_show_quota_options(struct seq_file *seq,
 #endif
 }
 
+static const char *token2str(int token)
+{
+        static const struct match_token *t;
+
+        for (t = tokens; t->token != Opt_err; t++)
+                if (t->token == token && !strchr(t->pattern, '='))
+                        break;
+        return t->pattern;
+}
+
 /*
  * Show an option if
  *  - it's set to a non-default value OR
@@ -1676,132 +1686,71 @@ static inline void ext4_show_quota_options(struct seq_file *seq,
 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
 {
         int def_errors;
-        unsigned long def_mount_opts;
         struct super_block *sb = root->d_sb;
         struct ext4_sb_info *sbi = EXT4_SB(sb);
         struct ext4_super_block *es = sbi->s_es;
+        const struct mount_opts *m;
 
-        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
-        def_errors     = le16_to_cpu(es->s_errors);
+#define SEQ_OPTS_PUTS(str) seq_printf(seq, "," str)
+#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "," str, arg)
 
         if (sbi->s_sb_block != 1)
-                seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
-        if (test_opt(sb, MINIX_DF))
-                seq_puts(seq, ",minixdf");
-        if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
-                seq_puts(seq, ",grpid");
-        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
-                seq_puts(seq, ",nogrpid");
-        if (sbi->s_resuid != EXT4_DEF_RESUID ||
-            le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
-                seq_printf(seq, ",resuid=%u", sbi->s_resuid);
+                SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
+
+        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
+                int want_set = m->flags & MOPT_SET;
+                if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
+                    (m->flags & MOPT_CLEAR_ERR))
+                        continue;
+                if (!(m->mount_opt & (sbi->s_mount_opt ^ sbi->s_def_mount_opt)))
+                        continue; /* skip if same as the default */
+                if ((want_set &&
+                     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
+                    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
+                        continue; /* select Opt_noFoo vs Opt_Foo */
+                SEQ_OPTS_PRINT("%s", token2str(m->token));
         }
+
+        if (sbi->s_resuid != EXT4_DEF_RESUID ||
+            le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
+                SEQ_OPTS_PRINT("resuid=%u", sbi->s_resuid);
         if (sbi->s_resgid != EXT4_DEF_RESGID ||
-            le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
-                seq_printf(seq, ",resgid=%u", sbi->s_resgid);
-        }
-        if (test_opt(sb, ERRORS_RO)) {
-                if (def_errors == EXT4_ERRORS_PANIC ||
-                    def_errors == EXT4_ERRORS_CONTINUE) {
-                        seq_puts(seq, ",errors=remount-ro");
-                }
-        }
+            le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
+                SEQ_OPTS_PRINT("resgid=%u", sbi->s_resgid);
+        def_errors = le16_to_cpu(es->s_errors);
+        if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
+                SEQ_OPTS_PUTS("errors=remount-ro");
         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
-                seq_puts(seq, ",errors=continue");
+                SEQ_OPTS_PUTS("errors=continue");
         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
-                seq_puts(seq, ",errors=panic");
-        if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
-                seq_puts(seq, ",nouid32");
-        if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
-                seq_puts(seq, ",debug");
-#ifdef CONFIG_EXT4_FS_XATTR
-        if (test_opt(sb, XATTR_USER))
-                seq_puts(seq, ",user_xattr");
-        if (!test_opt(sb, XATTR_USER))
-                seq_puts(seq, ",nouser_xattr");
-#endif
-#ifdef CONFIG_EXT4_FS_POSIX_ACL
-        if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
-                seq_puts(seq, ",acl");
-        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
-                seq_puts(seq, ",noacl");
-#endif
-        if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
-                seq_printf(seq, ",commit=%u",
-                           (unsigned) (sbi->s_commit_interval / HZ));
-        }
-        if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
-                seq_printf(seq, ",min_batch_time=%u",
-                           (unsigned) sbi->s_min_batch_time);
-        }
-        if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
-                seq_printf(seq, ",max_batch_time=%u",
-                           (unsigned) sbi->s_max_batch_time);
-        }
-
-        /*
-         * We're changing the default of barrier mount option, so
-         * let's always display its mount state so it's clear what its
-         * status is.
-         */
-        seq_puts(seq, ",barrier=");
-        seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
-        if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
-                seq_puts(seq, ",journal_async_commit");
-        else if (test_opt(sb, JOURNAL_CHECKSUM))
-                seq_puts(seq, ",journal_checksum");
+                SEQ_OPTS_PUTS("errors=panic");
+        if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
+                SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
+        if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
+                SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
+        if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
+                SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
         if (sb->s_flags & MS_I_VERSION)
-                seq_puts(seq, ",i_version");
-        if (!test_opt(sb, DELALLOC) &&
-            !(def_mount_opts & EXT4_DEFM_NODELALLOC))
-                seq_puts(seq, ",nodelalloc");
-
-        if (!test_opt(sb, MBLK_IO_SUBMIT))
-                seq_puts(seq, ",nomblk_io_submit");
+                SEQ_OPTS_PUTS("i_version");
         if (sbi->s_stripe)
-                seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
-        /*
-         * journal mode get enabled in different ways
-         * So just print the value even if we didn't specify it
-         */
-        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
-                seq_puts(seq, ",data=journal");
-        else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
-                seq_puts(seq, ",data=ordered");
-        else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
-                seq_puts(seq, ",data=writeback");
-
+                SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
+        if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
+                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
+                        SEQ_OPTS_PUTS("data=journal");
+                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
+                        SEQ_OPTS_PUTS("data=ordered");
+                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
+                        SEQ_OPTS_PUTS("data=writeback");
+        }
         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
-                seq_printf(seq, ",inode_readahead_blks=%u",
-                           sbi->s_inode_readahead_blks);
-
-        if (test_opt(sb, DATA_ERR_ABORT))
-                seq_puts(seq, ",data_err=abort");
-
-        if (test_opt(sb, NO_AUTO_DA_ALLOC))
-                seq_puts(seq, ",noauto_da_alloc");
+                SEQ_OPTS_PRINT("inode_readahead_blks=%u",
+                               sbi->s_inode_readahead_blks);
 
-        if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
-                seq_puts(seq, ",discard");
-
-        if (test_opt(sb, NOLOAD))
-                seq_puts(seq, ",norecovery");
-
-        if (test_opt(sb, DIOREAD_NOLOCK))
-                seq_puts(seq, ",dioread_nolock");
-
-        if (test_opt(sb, BLOCK_VALIDITY) &&
-            !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
-                seq_puts(seq, ",block_validity");
-
-        if (!test_opt(sb, INIT_INODE_TABLE))
-                seq_puts(seq, ",noinit_itable");
-        else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
-                seq_printf(seq, ",init_itable=%u",
-                           (unsigned) sbi->s_li_wait_mult);
+        if (test_opt(sb, INIT_INODE_TABLE) &&
+            (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT))
+                SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
 
         ext4_show_quota_options(seq, sb);
-
         return 0;
 }
 
@@ -3105,6 +3054,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                          "failed to parse options in superblock: %s",
                          sbi->s_es->s_mount_opts);
         }
+        sbi->s_def_mount_opt = sbi->s_mount_opt;
         if (!parse_options((char *) data, sb, &journal_devnum,
                            &journal_ioprio, 0))
                 goto failed_mount;